And I'm Robert Siegel. Vice President Joe Biden will be heading to Eastern Europe next week. The White House says he'll discuss the crisis in Ukraine during a visit to nearby Poland and Lithuania. Biden plans to hold talks with those two American allies. He'll also meet with the presidents of Estonia and Latvia. Today's announcement of the vice president's trip comes after Secretary of State John Kerry met with his Russian counterpart in London. With two days until Crimea votes on joining Russia, this was a last-ditch effort to find a political solution to the crisis. As NPR's Ari Shapiro reports, there was no breakthrough.

ARI SHAPIRO, BYLINE: At the U.S. ambassador's residence in London, Secretary Kerry spent all day in talks with Russian Foreign Minister Sergey Lavrov. The two men sat around a dining room table with their staff, and they took private laps around a massive lawn, kicking a soccer ball as they talked.

Finally, after six hours of negotiation, Lavrov spoke to reporters at the Russian ambassador's residence. Through an interpreter, he said there was no progress.

SERGEY LAVROV: (Through translator) As far as practical measures that could be taken by foreign partners of Ukraine, we don't have a common ground or similar views. We actually diverge on our views.

SHAPIRO: From the U.S. perspective, Russian President Vladimir Putin did not give Lavrov authority to negotiate about Crimea at all. Secretary Kerry spoke at his hotel.

SECRETARY JOHN KERRY: The foreign minister made it clear that President Putin is not prepared to make any decision regarding Ukraine until after the referendum on Sunday.

SHAPIRO: The West views the Crimea referendum as illegal and illegitimate. Kerry said neither the U.S. nor the European Union will recognize its results.

KERRY: There will be consequences if Russia does not find a way to change course. And we don't say that as a threat.

SHAPIRO: Between now and Sunday, it's possible that international heads of state will try to pressure Putin directly. If that doesn't work, European foreign ministers are meeting in Brussels on Monday. Depending on how the Crimea vote goes, that meeting could bring new sanctions against Russia. Ari Shapiro, NPR News, London. Transcript provided by NPR, Copyright NPR.